BASE GASKET BLOW OUT

[don46]

Copper head gaskets can work, what most people don't do is anneal them prior to installation, this is what Mark was referring to with the Butane torch, If you just install them without annealing them I can almost guarantee they will leak. If given the choice I would use a stock or Cometic headgasket over the copper, but, in some cases that's the only alternative for special applications. One of my motors uses a copper head gasket, I use a hopcolite sealer and have annealed the gasket, it doesn't leak, of course I'm afraid to take it apart because I know it will next time.

[BDI]

when i install a cylinder, i install the cylinder with out the piston and base gasket. And torque to spec. and look for gaps around the surface. and use small feeler gauge for clearance. Kawasaki stud are known to be on the soft side. we had this problem on the jetski motors. the problem most of the time are high spots around the area of the stud. I just had the buttom of my cylinder cut and it was .004 off.

 
That is what was wrong with my cylinder deck it was like the stress from tightning the head nuts pulled the aluminum up around the studs making a high spot around every stud. That is why the fiber head gasket would last a couple hours and the copper head gasket would not seal at all even though It had been properly annealed and sprayed with the most expensive sealant on earth a.k.a. Hylomar.

[monster malibu]

Hey guys, I called Cometic and they recommended their Nitro Coated Aluminum base gasket for my bike. These gaskets are for the stock bore 86mm, the part # is B0035018AFM if anyones interested. They don't have the gaskets in stock, but will make them in three days.

[BDI]

What ever happened Is your bike running yet?

[monster malibu]

I got the bike back together and my base gasket problem is gone. My bike runs fine again but it's bow season, so my riding is pretty limited.

[BDI]

Ride on glad to hear It. What did you think of the gaskets?

[monster malibu]

I thought the gaskets were kind of thin and flimbsy, but they work, that's what counts. I got my gaskets in three days just like Cometic said,that was cool.

[BDI]

The first time I used them I was skeptical. They seem weird at first but they work great and wait until take your bike apart then you will like them a lot.

[monster malibu]

I bought an extra base gasket just in case of another blowout. The head gasket was around $22, and the shipping on the three gaskets was $10.45 WHAT A RIP OFF!!! All the gaskets couldv'e been sent in a envelope and shipped for probably a few bucks.

[BDI]

yes I'm going threw the same thing with them right now I wanted my gaskets by the week end but they wanted an arm and a leg to ship them when they could send them priority mail for less then ten bucks and I would easily have them for the weekend.

[mxaniac]

Old topic I know but I just had my base gasket blow out.  Never even heard of that happening on a 2-stroke before.  My first thought was I'd wished I'd used Cometic last fall when I put it together.  Met the founder in a bar one night, heck of a nice guy.  Regardless, my point in posting in an old topic is that this thread is the first hit in google when I searched on the topic.  I can confirm, yes the KX500 base gasket will blow and Cometic makes a nice gasket and I wish I had used one last time.